地球物理警报广播
geophysical alert broadcast
广播报时信号
pip
Time signal in radio broadcasting
广播广告发展潜力
potential development of radio ads
广播广告优势
advantages of radio advertising
火警广播系统
public-fire alarm address system
群播广播封包
Multicast and Broadcast Packets
电脑化火警警报传送系统
computerized fire alarm transmission system